<template>
  <div class="home-category">
    <!--
      骨架屏占位核心？
      1. 没有数据的时候 =》按照页面的结构，显示骨架屏结构
      2. 有数据的时候 =》不显示骨架屏结构
     -->
    <ul class="menu" v-if="leftNavs.length > 0">
      <!-- 一级 -->
      <li v-for="item in leftNavs" :key="item.id">
        <RouterLink to="/">{{ item.name }}</RouterLink>
        <!-- 二级 -->
        <template v-if="item.children">
          <RouterLink v-for="sub in item.children" :key="sub.id" to="/">
            {{ sub.name }}
          </RouterLink>
        </template>

        <!-- 弹层：分类推荐商品 -->
        <div class="layer">
          <h4>分类推荐 <small>根据您的购买或浏览记录推荐</small></h4>
          <ul>
            <li v-for="good in item.goods" :key="good.id">
              <RouterLink :to="`/detail/${good.id}`">
                <img :src="good.picture" alt="" />
                <div class="info">
                  <p class="name ellipsis-2">
                    {{ good.name }}
                  </p>
                  <p class="desc ellipsis">{{ good.desc }}</p>
                  <p class="price"><i>¥</i>{{ good.price }}</p>
                </div>
              </RouterLink>
            </li>
          </ul>
        </div>
      </li>
    </ul>
    <ul class="menu" v-else>
      <li v-for="item in 9" :key="item">
        <!-- 第一个：占位一级分类 -->
        <XtxSkeleton
          style="margin-right: 6px"
          width="32"
          height="20"
          background="rgba(255,255,255,.7)"
        />
        <!-- 后两个：占位二级分类 -->
        <XtxSkeleton
          style="margin-right: 6px"
          width="56"
          height="20"
          background="rgba(255,255,255,.7)"
        />
        <XtxSkeleton width="56" height="20" background="rgba(255,255,255,.7)" />
      </li>
    </ul>
  </div>
</template>

<script>
import { computed } from 'vue-demi'
import { useStore } from 'vuex'
export default {
  name: 'HomeCategory',
  setup () {
    /**
     * 获取左侧分类数据？=> 头部菜单数据共用一份数据
     * 1. 获取vuex实例=》useStore()
     * 2. 借助computed计算属性函数 =》computed() => cate模块 =》== 1级 + 2级（前两个） ==
     */
    const store = useStore()
    const leftNavs = computed(() => {
      // 真正数据
      return store.state.cate.cateList.map((item) => {
        return {
          id: item.id,
          name: item.name,
          goods: item.goods, // 分类推荐商品列表
          children: item.children.slice(0, 2)
        }
      })
      // 方便测试
      // return []
    })
    return { leftNavs }
  }
}
</script>

<style scoped lang='less'>
.home-category {
  width: 250px;
  height: 500px;
  background: rgba(0, 0, 0, 0.8);
  position: relative;
  z-index: 99;
  // 左侧菜单
  .menu {
    > li {
      padding-left: 40px;
      height: 55px;
      line-height: 55px;
      a {
        margin-right: 4px;
        color: #fff;
        &:first-child {
          font-size: 16px;
        }
      }

      // 弹层默认不显示
      .layer {
        width: 990px;
        height: 500px;
        background: rgba(255, 255, 255, 0.8);
        position: absolute;
        left: 250px;
        top: 0;
        display: none;
        padding: 0 15px;
        h4 {
          font-size: 20px;
          font-weight: normal;
          line-height: 80px;
          small {
            font-size: 16px;
            color: #666;
          }
        }
        ul {
          display: flex;
          flex-wrap: wrap;
          li {
            width: 310px;
            height: 120px;
            margin-right: 15px;
            margin-bottom: 15px;
            border: 1px solid #eee;
            border-radius: 4px;
            background: #fff;
            &:nth-child(3n) {
              margin-right: 0;
            }
            a {
              display: flex;
              width: 100%;
              height: 100%;
              align-items: center;
              padding: 10px;
              &:hover {
                background: #e3f9f4;
              }
              img {
                width: 95px;
                height: 95px;
              }
              .info {
                padding-left: 10px;
                line-height: 24px;
                overflow: hidden;
                .name {
                  font-size: 16px;
                  color: #666;
                }
                .desc {
                  color: #999;
                }
                .price {
                  font-size: 22px;
                  color: @priceColor;
                  i {
                    font-size: 16px;
                  }
                }
              }
            }
          }
        }
      }
      // 显示弹层
      &:hover {
        background: @xtxColor;
        .layer {
          display: block;
        }
      }
      // end
    }
  }
}
</style>
